Washing machine with improved agitation



Dec. 4, 1962 J. GILLESSEN WASHING MACHINE WITH IMPROVED AGITATION FiledApril 27, 1960 INVENTOR JOSEF LEON/mo 0/41.: s selv 5 m ha V 4 Ill? n n2n nrra was 7 s United States Patent Ofihce Patented K ee, l, lib-3,4?66521 WASHING MACHINE WlTH IMPRGVED AGITATION Josef LeonardGiliessen, Dusseldorf, Germany, assignor to Maschinenfahrilt PeterPfenningsherg Gannbll, Dusseldorf-Oberiiassel, Germany Filed Apr. 27,196i Ser. No. 25,6?) Claims priority, application Germany May 29, E59 9Claims. (Cl. 6823) This invention relates to Washing machines intendedespecially for household use and having washing drums which are rotatedabout vertical axes, and have charging apertures in their tops There areknown washing machines in which, during the washing process, thematerial being washed is handled mechanically by a washing stirrer, alsocalled a pulsator or agitator. In most cases the drum remains stationaryduring this process. After the washing process has come to an end, thedrum which is able to rotate about a vertical axis, and in certain casesthe agitator too, are rotated rapidly, so that when the outlet is openedthe material may be spin-dried. This washing process requires acomparatively high ratio of washing liquid to material being washed.Besides this, during the process the material being washed is subject toa considerable amount of wear due to the inflexible movement of theagitator.

In the case of another known washing machine, in which the washingcontainer is upright, the material to be washed is constantly turned bya stream of liquid which is directed radially in relation to thecontainer floor and climbs up its walls, the container being at rest.Thus the washing is handled mechanically too, whilst the washing liquidflows repeatedly back to a pump with which the machine is provided andby means of which the liquid is again introduced at the floor of the container. This process is in essence less damaging than the first. But apowerful flow of liquid is required for the washing to be treatedeffectively. In this case also a high ratio of washing liquid tomaterial being washed is necessary. A powerful pump is required also.Apart from this it has come to light that, in relation to the mechanicalagitator, this device is not very effective and so, in general, longerperiods of washing are necessary.

The problem with which the present invention is concerned lies inproviding a washing machine, especially intended for household use,which does not have the shortcomings mentioned above and which, althoughhaving a most simple form of construction, none the less makes effectivelaundering of even delicate articles possible.

According to the present invention, the floor of the drum of a washingmachine having a drum which is rotatable about a vertical axis slopesupwards from the inside towards the periphery and the drum has avariable speed drive. The floor of the drum is preferably conical. Thedrum is revolved at a high speed and then again at a low speed severaltimes whilst the washing process is under way. The effect is that thematerial to be washed repeatedly climbs up the floor of the washing drumand then falls back towards the center of the drum again. For, when thespeed of rotation of the drum increases, centrifugal force acts on thematerial to be washed, one component of which takes effect in adirection parallel to the floor of the drum as a result of which thematerial climbs upwards, whilst its other component is normal to thesurface of the floor of the drum and this presses the material to bewashed against it. The floor of the drum is preferably provided withcorrugations in the manner of a washboard. These by preference shouldrun concentrically with the axis of and rotation of the drum. Wheneverthe material to be washed ascends or descends the floor of the drum, thefloor has the effect of a washboard on it, this effect being at the sametime augmented by means of the additional pressing of the materialagainst the floor whilst it is ascending.

In a washing machine which has a washing drum provided withperforations, and which is housed in an outer container, the washingdrum has, in accordance with a further feature of the invention, anunperforated roof in which the charging opening is situated. This roofis turned down slightly around the charging opening. The outer containerconforms to the shape of the washing drum surrounding it completely, andat only a slight distance from it. At the top of the outer containerthere is a charging opening which may be closed by means of a cover.Thus when the speed of rotation of the drum increases, not only is thematerial to be washed pressed against the drum floor and thus at thesame time lifted, but the washing liquid also is forced radially throughthe material to be washed. As a result of this the water enters thenarrow annular space between the drum and the outer container via theperforations in the drum. Here the water climbs up to the top, returningonce more to the drum via the charging aperture. In this manner acirculation of the washing liquid is effected without an additional pumpbeing necessary for this purpose.

In order that the washing liquid can flow back into the charging openingof the drum roof via the roof, without being prevented by centrifugalforce, there is a fixed baflle plate disposed above the Washing drum.This plate conforms to the shape of the drum roof and its outer edge isturned downwards and lies at a very small distance from the drum roof.

An example of a washing machine in accordance with the invention isillustrated in the accompanying drawing in which:

FIGURES l to 3 are diagrammatic vertical axial sections through themachine, each figure illustrating a different phase of the washingoperation;

FIGURE 4 is a diagram showing some of the forces which arise during thewashing operation; and

FTGURE 5 is a graph showing the relationship between the speed ofrotation of the drum and time.

As shown in FIGURES 1 to 3, a Washing drum 1. which has perforations 2,is rotatable about a vertical axis. The drum has a floor 3 which ascendsconically outwards. The floor 3 is provided with corrugations 3, like awashboard, which in this case are concentric with the axis of rotationof the drum. The drum has at the top an unperforated roof 4 having acentral charging aperture 5'. The roof 4 is slightly turned down aroundthe charging aperture. The floor 3 has a flange 6 to which a drivingshaft 7 is attached. The shaft 7 is connected via a coupling 8 to amotor 9. The washing drum 1 is encased by an exterior container it whichis constructed to conform to the shape of the drum and lies at allpoints at a slight distance from it. There is thus a space ill betweenthe drum 1 and the exterior container It A roof 12 of the container 10has a central charging aperture 13 which may be closed by means of a lid14. The aperture 13 coincides with the charging aperture 5 of thedrum 1. A drain 15 attached to the exterior wall of the container 10,which communicates with the inner space of the container, terminates inan outlet channel 17 for the washing liquid. The channel 17 has ashut-off valve 16. Above the washing drum 1 there is a baffle plate 21which conforms to the shape of the roof 4 and is fastened by means ofbrackets 21a to the roof 12 of the container lltl. The outer rim 22 ofthe baffle plate 21 lies extremely close to 0.3 the roof 4 of the drumbut does not touch it. The purpose of the bafile plate will be explainedbelow.

In FIGURE 1 the charge of the machine is shown to be in that positionwhich it assumes after the washing drum 1 has been filled up. When thedrum 1 is rotated by means of the motor 9 an increasing centrifugalforce is exercised on the material to be washed as the rate of rotationbecomes greater. This tends to move the material in an outward radialdirection. The conically ascending floor 3 of the drum 1 has the effectof an inclined plane during this process. The splitting up of thehorizontally exective centrifugal force into two components is madeclear in FIGURE 4, in which the centrifugal force is Z, the component ofthis force taking elfect in a direction parallel to the inclined plane 3is V, and the component taking effect in a direction normal to thesurface 3 is P. :The force P presses the charge against the floor 3,whereas force V moves the charge up the floor 3, the articles lyingfurthest away from the center being displaced with the largest force.This is indicated in FIG- URE 2. The magnitude of the force Z depends onthe speed of rotation and the magnitude of both its components P and Vdepend in addition on the angle of inclination of the floor 3. When thespeed of rotation of the drum is decreased the charge slides downwardsonce more and becarnes slack at the same time.

When the rotational speed is increased the washing liquid is subjectedat the same time to a radial, outwardly directed pressure which grows inmagnitude, and which forces it through the material to be washed,through the perforations of the drum and into the gap towards the top,corresponding to the direction indicated in FIGURE 2 by the arrow 18.The washing liquid arrives, therefore, at the gap 19, between the roofof the container 12 and the bailie plate '21, and flows via this (asshown by the arrow Ed in FIGURE 2) through the charging aperture backinto the drum 1. Without the presence of the bafiie plate 241 therotating drum roof 4 would tend to project the liquid in the gap 19outwards, thereby impeding the flowbacl; of the liquid through theopening 5.

In FIGURE 3 there is an illustration of how the material to be Washedclimbs up into the top of the drum above a line 23 Where the diameter ofthe drum is greatest, when the rotational speed of the drum is increasedduring the spin-drying process. When the valve 16 is opened, the Washingliquid expelled from the drum and from the material to be washed canflow off via the channel 17.

The washing machine illustrated in FIGURES 13 can, by way of example, berun as shown in FIGURE 5. In the graph shown here, time t is plotted asthe abscissa, and the speed of rotation n of the drum is plotted as theordinate n. Within the time t the rotational speed of the drum increasesto the maximum rotational speed for the washing process n This speed isafterwards maintained for the time t At this point the motor is sloweddown or switched off and the washing drum comes to rest after a time iNow the direction of rotation of the drum is reversed, so that theprocess which has taken place during times t, to 1 can be repeated butin the opposite direction of rotation. The broken line in FIGURE 5 inthe time internal 22, indicates this. This variation in the direction ofrotation is repeated throughout the whole duration t of the washingprocess. As a result of the reversal of the rotation of the drum, tightknotting up of the material to be washed is avoided. This is also thecase with washing machines which have a horizontally arranged drum andwhich can work in reverse, except that in such machines the variationsin the direction of rotation occur in a more irregular fashion.

In order that the machine may be switched over to the spin-dryingoperation, the washing machine is accelerated to the speed 11 necessaryfor spin-drying, this speed being maintained for a time t This increasein the speed of rotation can be obtained by means of a motor with avariable-speed transmission or, preferably, with a polechangeable motorhaving interdependent coils and a ratio of the number of pole pairsamounting to 1:3 at least.

The washing drum may of course have some shape other than thatindicated. The angle of inclination of the floor of the drum can also bedifferent. If the conical drum floor, for example, ascends more abruptlyin an outward direction, it is possible to allow the charge which hasascended to slide down again and become slack without stopping the drumagain at any stage. The drum drive can also be obtained by means of aV-belt or a toothed reduction gear. Moreover it is not absolutelynecessary for the drum to be reversible. Further, as is already commonpractice, it is possible to admit fresh water to the machine eitherconstantly or at measured intervals whilst the washing process is goingon, the dirty liquid being expelled. Finally the machine can becontrolled either semi-automatically or fully automatically by a programcontrol.

I claim:

1. In a washing machine, in combination, a clothes receptacle rotatableabout a generally upright axis, said receptacle having a floor slopingconically upwardly and outwardly from said axis at a substantial angleof in:

clination to the horizontal, and driving means for rotating saidreceptacle at varying speeds duringa washing operation whereby a chargecontained in said rcceptacle is displaced upwardly along said floor by acentrifugal force due to higher speeds and slides down therealong upon areduction of said force at lower speeds, said fioor being formed withcorrugations extending generally transversely to the direction ofdisplacement of said charge therealong.

2. In a washing machine having a washing period and an extractingperiod, in combination, a perforated clothes receptacle rotatable abouta generally upright axis, said receptacle having a corrugated floorsloping conically upwardly and outwardly from said axis at a substantialangle of inclination to the horizontal, and driving means for rotatingsaid receptacle at periodically varying speeds during said washingperiod whereby a charge contained in said receptacle is displacedupwardly along said floor by a centrifugal force due to higher speedsand slides down therealong upon a reduction of said force at lowerspeeds, said floor being formed with corrugations extending generallytransversely to the direction of displacement of said charge therealong,said driving means being constructed and arranged to rotate saidreceptacle at a speed greater than said higher speeds during saidextracting period.

3. In a wshing machine, in combination, a housing, an open-top clothesreceptacle rotatable in said housing about a generally upright axis,said receptacle having an upwardly diverging conical floor sloping at asubstantial angle to the horizontal while being centered on said axisand provided with inwardly projecting axially spaced annularcorrugations centered on said axis and adapted to rub against a chargein said receptacle as the charge is displaced along said floor, anddriving means for rotating said receptacle at periodically varyingspeeds during a washing operation whereby the charge contained in saidreceptacle is displaced upwardly along said floor by a centrifugal forcedue to higher speeds and slides down therealong upon a reduction of saidforce at lower speeds.

4. In a washing machine, in combination, a housing, an open-top clothesreceptacle rotatable in said housing about a generally upright axis,said receptacle having an upwardly diverging conical floor centered onsaid axis at a substantial angle of inclination to the horizontal andprovided with inwardly projecting axially spaced annular corrugationscentered on said axis and adapted to rub against a charge in saidreceptacle as the latter is displaced along said floor, inlet means forintroducing an initial quantity of a washing liquid into saidreceptacle, said housing being formed with wall portions paralleling theouter wall portions of said receptacle and forming an annular spacetherebetween, said floor being provided with a passage connecting theinterior of said receptacle with said annular space, and driving meansfor rotating said receptacle at alternately higher and lower speedsduring a washing operation whereby a charge contained in said receptacleis displaced upwardly along said floor by a centrifugal force due tohigher speeds and slides down therealong upon a reduction of said forceat lower speeds, said washing liquid being centrifugally dischargeabiefrom said receptacle through said passage into said space and returningfrom said space to said receptacle through the open top thereof.

5. In a washing machine, in combination, a housing. an open-top clothesreceptacle rotatable in said housing about a generally upright axis,said receptacle having an upwardly diverging conical floor centered onsaid axis at a substantial angle of inclination to the horizontal andprovided with inwardly projecting axially spaced annular corrugationscentered on said axis and adapted to rub against a charge in saidreceptacle as the latter is displaced along said floor, inlet means forintroducing an initial quantity of a washing liquid into saidreceptacle, said housing being formed with wall portions paralleling theouter wall portions of said receptacle and forming an annular spacetherebetween in communication with the open top of said receptacle, saidfloor being provided with numerous perforations connecting the interiorof said receptacle with said annular space, and driving means forrotating said receptacle at alternately higher and lower speeds during awashing operation whereby a charge contained in said receptacle isdisplaced upwardly along said floor by a centrifugal force due to higherspeeds and slides down therealong upon a reduction of said force atlower speeds, said washing liquid being centrifugally dischargeable fromsaid receptacle through perforations into said space and returning fromsaid space to said receptacle through the open top thereof.

6. The combination according to claim 5 wherein said receptacle isformed with a cover plate extending transversely to said axis andprovided with a central opening constituting the open top of saidreceptacle, said housing being formed with stationary bafile meanssurrounding said opening and closely overlying said roof for conductingwash liquid from said space to said opening.

7. The combination according to claim 5 wherein said receptacle furtherhas a perforated cylindrical portion merging into said conical floor atthe widest diameter of the latter.

8. The combination according to claim 7 wherein the height of saidconical floor is at least equal to that of said cylindrical portion.

9. The combination according to claim 5 wherein said driving means isreversible.

References Cited in the file of this patent UNITED STATES PATENTS1,345,761 Fulton July 6, 1920 1,376,227 Rabezzana Apr. 26, 19211,390,678 De Laney Sept. 13, 1921 1,629,761 Woodrow May 24, 19271,825,651 Barrett Oct. 6, 1931 2,289,162 Anionsen July 7, 1942 2,292,815Bariffi Aug .11, 1942 2,506,882 Lipscomb May 9, 1950 FOREIGN PATENTS198,951 Switzerland Oct. 1, 1938

